---
product_id: 74978866
title: "Mongoose Legion Kids Freestyle Sidewalk BMX Bike"
brand: "mongoose"
price: "$909.99"
currency: USD
in_stock: false
reviews_count: 13
url: https://www.desertcart.us/products/74978866-mongoose-legion-kids-freestyle-sidewalk-bmx-bike
store_origin: US
region: United States of America
---

# 20-inch durable wheels Precision 25x9T BMX gearing Hi-Ten steel frame built to last Mongoose Legion Kids Freestyle Sidewalk BMX Bike

**Brand:** mongoose
**Price:** $909.99
**Availability:** ❌ Out of Stock

## Summary

> 🔥 Own the streets with the Mongoose Legion L20 BMX! 🚀

## Quick Answers

- **What is this?** Mongoose Legion Kids Freestyle Sidewalk BMX Bike by mongoose
- **How much does it cost?** $909.99 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/74978866-mongoose-legion-kids-freestyle-sidewalk-bmx-bike)

## Best For

- mongoose enthusiasts

## Why This Product

- Trusted mongoose brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Smooth Control:** Aluminum U-brakes and levers deliver precise stopping power for confident handling.
- • **Grip & Stability:** Wide 20” x 2.3” BMX tires on aluminum 36H rims provide traction on street, park, and dirt.
- • **Reliable Drivetrain:** One-piece forged steel cranks with 25T alloy chainring ensure efficient power transfer.
- • **Optimized Ride Geometry:** 20.25-inch top tube and 8-inch rise handlebars tailored for intermediate riders 4’8”–5’4”.
- • **Street-Ready Durability:** Hi-Ten steel frame and fork engineered for freestyle stunts and everyday rides.

## Overview

The Mongoose Legion L20 is a 20-inch freestyle BMX bike designed for intermediate riders between 4’8” and 5’4”. Featuring a durable Hi-Ten steel frame, precision 25x9T gearing, and wide BMX tires on aluminum rims, it delivers reliable performance for street, park, and dirt riding. With aluminum U-brakes and a responsive handlebar setup, this bike offers smooth control and lasting durability, backed by a 5-year frame warranty.

## Description

For 45 years, Mongoose has been in the dirt, down the trails, and on the ramps. With the Legion series, Mongoose offers a full line of freestyle BMX bikes for riders of all ages and ability levels. When you are almost ready for a 20” bike, but not quite there, the Legion L18 is a great in-between ride. The Legion L18 features a hi-ten steel frame (16. 9” top tube). the L18 hi-ten steel 6. 5” Rise handlebar and 40 mm stem are designed for precision riding, while the aluminum single wall 28H rims and 2. 3” BMX tires offer grip and durability. The 25x9t gearing with one-piece forged steel 140 mm crank and American loose ball Bottom bracket offer a clean, reliable drivetrains. An aluminum u-brake provides speed control, while the hi-ten steel BMX fork with 1-1/8" Thread less steered helps maximize performance. This bike ships ready to be assembled and comes with a 5-year limited on the frame and a 1-year limited on parts.

Review: Extremely Easy to Assemble. Bike Looks Amazing. M8x1.25 Tap May be Needed. - The bike from the pictures looked pretty cool. I didn't realize how beautiful this bike would be until it came in the mail. I purchased the Legion Mag in orange for my 8 year old. It was great to see his reaction on Christmas when receiving this bike. He was so excited. I read some other reviews from reviewers who had complaints on the difficulty of assembling the bike and in my opinion the people having trouble assembling the bike must be blatantly ignorant or illiterate. The instructions for assembly are written so a teenager could assemble this bike, with clearly labeled diagrams and more in depth explanations than what is necessary for assembly. The instructions on assembly are excellent and I had almost no trouble assembling the bike without them until it came to adjusting the brakes. I assembled the entire bike without instructions except for the brakes because it is just self explanatory. I was also able to assemble the brakes without any trouble or needing the instructions although I did refer to them for proper adjustment and alignment protocols. The only issue I had when assembling the bike is when I got to the point of attaching the handlebars to the handlebar binder assembly attached to the stem. The four socket cap screws that tighten down on the handlebar binder bracket would not thread easily. I felt as though I would break the screws or destroy the threads if I attempted to tighten them down far enough to grip the handlebars. There was too much paint in the threaded holes and also the tolerances on the machining of the threads was not great. I have included some pictures showing just how much paint was removed from tapping and also chips from burs in the threaded holes from poor tolerance drilling and tapping at the factory. In order to fix this problem I grabbed a tap handle and a M8x1.25 normal thread tap and tapped the holes. I would give this bike a 4.9 out of 5 if I could just because I needed to tap these holes and a tap was not listed as a required tool. I don't think many people will have problems assembling the bike even if they have this issue and need to tap the four holes as these are the only holes that need anything to be screwed into. Honestly if you don't at the very least know how to use a tap and die set you probably shouldn't be assembling a bike as it's not safe to do so if you're not familiar with basic tools. You could wind up hurting your child from pure negligence if you don't know how to use basic hand tools to assemble this bike properly. My suggestion is that you take it to a local bike shop and pay $30-$40 to have them assemble the bike and adjust the brakes if you don't know what you are doing. I assume some people who buy this bike will do just that with the majority of people knowing how basic hand tools work and them being able to assemble it themselves. Overall the bike is amazing, my son loves it, it was extremely easy to assemble, and I recommend you tap the holes on the handlebar binder even if it doesn't need it as it will allow you to make a more secure connection. Please don't listen to people complaining about difficult assembly as it was extremely easy even the detangler brakes something of which I've never seen or dealt with on a bike before. The instructions are very clear on how to hook the brakes up and how to adjust them properly and I was actually surprised how easy it was to assemble the brakes because I was expecting something very difficult based on the reviews but it turns out these brakes are easier to assemble than normal brakes.
Review: GREAT BIKE! HIGHLY RECOMMEND. - I assembled it today and it took 20 minutes tops. If you have ever assembled anything before then it should be fairly easy. I didn't open the manual for instructions besides confirming my suspicion of which direction the large washers with the raised ridge were orientated. The raised edge goes inwards towards the forks FYI. The brakes were very easy to adjust, I seen reviews stating how difficult they were to adjust or setup. Not sure why but they couldn't be a more basic setup. I also recommend making sure the bearings in the fork tube are not to tight. The ones on the bike I received were WAY to tight and you could physically feel individual bearings moving when you turned the handlebars. After adjusting accordingly it moves nice and smooth. I saw a review that their stalk broke and this could be why it broke. If they are to tight you can damage them and eventually the stalk as well. I definitely recommend this kids freestyle bike. Brings back memories of my bmx bikes back in the 80's. The orange color is awesome as well. Especially since my grandson is a big Oregon State beavers fan.

## Features

- Legion L18 is the perfect in-between option for our kids who wants the features of a standard 20 inch BMX bikes but require a slightly smaller frame, rider height recommendation is 3'8" to 4'8"
- Durable Hi-Ten steel frame with 16.9” top tube length
- Single speed drivetrain features a 140 mm one-piece crank with a 25T alloy chainring and American loose ball bottom bracket
- Wheelset features 18” x 2.3” tires mounted on aluminum single wall 28H rims with 3/8” female axle front hub and 9T cog sealed bearing cassette rear hub
- Aluminum U-brake provides precision speed control, while the Hi-Ten steel handlebar and fork are joined by a 40 mm stem and threadless sealed integrated headset for maximum steering performance

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B07WLK1DXQ |
| Additional Features | Aluminum Frame, BMX, freestyle |
| Age Range (Description) | Little Kid |
| Age Range Description | Little Kid |
| Best Sellers Rank | #41,054 in Sports & Outdoors ( See Top 100 in Sports & Outdoors ) #76 in Kids' Bicycles |
| Bicycle Drivetrain Type | Single-speed |
| Bike Type | BMX Bike |
| Brake Style | U Brake |
| Brand | Mongoose |
| Brand Name | Mongoose |
| Color | Silver/L18 |
| Customer Reviews | 4.4 out of 5 stars 4,024 Reviews |
| Frame Material Type | High Tensile Steel |
| Gear Type | cassette |
| Global Trade Identification Number | 00038675187160 |
| Included Components | Bicycle, Legion L18 |
| Intended Riding Terrain | BMX Terrain |
| Item Type Name | Freestyle BMX Bike |
| Item Weight | 12 kg |
| Manufacturer | Pacific Cycle, Inc. |
| Minimum User Height | 38 inches |
| Model Name | Legion Novice |
| Model Number | M41700U10OS-PC |
| Model Year | 2020 |
| Number Of Speeds | 1 |
| Number of Handles | 2 |
| Number of Speeds | 1 |
| Power Source | Pedal power (human energy transferred through a drivetrain) |
| Seat Material | Plastic |
| Size | 18-Inch Wheels/L18 |
| Specific Uses For Product | Trail |
| Style Name | L18 |
| Suspension Type | No Suspension |
| UPC | 038675187160 |
| Unit Count | 1 Count |
| Warranty Description | Limited lifetime warranty on frame and one year warranty on parts |
| Warranty Type | Limited |
| Wheel Material | Aluminum |
| Wheel Size | 18 inches |

## Product Details

- **Age Range (Description):** Little Kid
- **Bike Type:** BMX Bike
- **Brand:** Mongoose
- **Color:** Silver/L18
- **Frame Material:** High Tensile Steel
- **Included Components:** Bicycle, Legion L18
- **Number of Speeds:** 1
- **Special Feature:** Aluminum Frame, BMX, freestyle
- **Suspension Type:** No Suspension
- **Wheel Size:** 18 inches

## Images

![Mongoose Legion Kids Freestyle Sidewalk BMX Bike - Image 1](https://m.media-amazon.com/images/I/81wOqWmMUUL.jpg)
![Mongoose Legion Kids Freestyle Sidewalk BMX Bike - Image 2](https://m.media-amazon.com/images/I/61ReNjn9FnL.jpg)
![Mongoose Legion Kids Freestyle Sidewalk BMX Bike - Image 3](https://m.media-amazon.com/images/I/61JOnI0ObYL.jpg)
![Mongoose Legion Kids Freestyle Sidewalk BMX Bike - Image 4](https://m.media-amazon.com/images/I/71XuuNDDCTL.jpg)
![Mongoose Legion Kids Freestyle Sidewalk BMX Bike - Image 5](https://m.media-amazon.com/images/I/61PCvlLwctL.jpg)

## Available Options

This product comes in different **Color, Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Extremely Easy to Assemble. Bike Looks Amazing. M8x1.25 Tap May be Needed.
*by D***E on December 30, 2020*

The bike from the pictures looked pretty cool. I didn't realize how beautiful this bike would be until it came in the mail. I purchased the Legion Mag in orange for my 8 year old. It was great to see his reaction on Christmas when receiving this bike. He was so excited. I read some other reviews from reviewers who had complaints on the difficulty of assembling the bike and in my opinion the people having trouble assembling the bike must be blatantly ignorant or illiterate. The instructions for assembly are written so a teenager could assemble this bike, with clearly labeled diagrams and more in depth explanations than what is necessary for assembly. The instructions on assembly are excellent and I had almost no trouble assembling the bike without them until it came to adjusting the brakes. I assembled the entire bike without instructions except for the brakes because it is just self explanatory. I was also able to assemble the brakes without any trouble or needing the instructions although I did refer to them for proper adjustment and alignment protocols. The only issue I had when assembling the bike is when I got to the point of attaching the handlebars to the handlebar binder assembly attached to the stem. The four socket cap screws that tighten down on the handlebar binder bracket would not thread easily. I felt as though I would break the screws or destroy the threads if I attempted to tighten them down far enough to grip the handlebars. There was too much paint in the threaded holes and also the tolerances on the machining of the threads was not great. I have included some pictures showing just how much paint was removed from tapping and also chips from burs in the threaded holes from poor tolerance drilling and tapping at the factory. In order to fix this problem I grabbed a tap handle and a M8x1.25 normal thread tap and tapped the holes. I would give this bike a 4.9 out of 5 if I could just because I needed to tap these holes and a tap was not listed as a required tool. I don't think many people will have problems assembling the bike even if they have this issue and need to tap the four holes as these are the only holes that need anything to be screwed into. Honestly if you don't at the very least know how to use a tap and die set you probably shouldn't be assembling a bike as it's not safe to do so if you're not familiar with basic tools. You could wind up hurting your child from pure negligence if you don't know how to use basic hand tools to assemble this bike properly. My suggestion is that you take it to a local bike shop and pay $30-$40 to have them assemble the bike and adjust the brakes if you don't know what you are doing. I assume some people who buy this bike will do just that with the majority of people knowing how basic hand tools work and them being able to assemble it themselves. Overall the bike is amazing, my son loves it, it was extremely easy to assemble, and I recommend you tap the holes on the handlebar binder even if it doesn't need it as it will allow you to make a more secure connection. Please don't listen to people complaining about difficult assembly as it was extremely easy even the detangler brakes something of which I've never seen or dealt with on a bike before. The instructions are very clear on how to hook the brakes up and how to adjust them properly and I was actually surprised how easy it was to assemble the brakes because I was expecting something very difficult based on the reviews but it turns out these brakes are easier to assemble than normal brakes.

### ⭐⭐⭐⭐⭐ GREAT BIKE! HIGHLY RECOMMEND.
*by B***Y on September 1, 2026*

I assembled it today and it took 20 minutes tops. If you have ever assembled anything before then it should be fairly easy. I didn't open the manual for instructions besides confirming my suspicion of which direction the large washers with the raised ridge were orientated. The raised edge goes inwards towards the forks FYI. The brakes were very easy to adjust, I seen reviews stating how difficult they were to adjust or setup. Not sure why but they couldn't be a more basic setup. I also recommend making sure the bearings in the fork tube are not to tight. The ones on the bike I received were WAY to tight and you could physically feel individual bearings moving when you turned the handlebars. After adjusting accordingly it moves nice and smooth. I saw a review that their stalk broke and this could be why it broke. If they are to tight you can damage them and eventually the stalk as well. I definitely recommend this kids freestyle bike. Brings back memories of my bmx bikes back in the 80's. The orange color is awesome as well. Especially since my grandson is a big Oregon State beavers fan.

### ⭐⭐⭐⭐⭐ Amazing Color!!!
*by B***S on September 1, 2026*

Great product, my son is happy. It just remains to try it on the street.

## Frequently Bought Together

- Mongoose Legion Kids Freestyle Sidewalk BMX Bike, Beginner Riders, Boys and Girls, 16-20-inch Wheels, Hi-Ten Steel Frame, Micro Drive BMX Gearing
- Zelerdo 2 Pairs Aluminum Alloy Bike Pegs for Mountain Bike Cycling Rear Stunt Pegs Fit 3/8 inch Axles
- Mongoose Legion Kids Freestyle BMX Bike, Intermediate Rider, Boys and Girls Bikes, 20-Inch Wheels, Hi-Ten Steel Frame, Micro Drive 25x9T BMX Gearing

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-09-27*